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<p>Could be. Although, in fairness, post-pregnancy may not offer a tightly-controlled experimental baseline!</p>
<p>I listened to an terrific new podcast interview last night with Dr. Steven Phinney. MD (Stanford), PhD (MIT) who has done some of the early low-carb research, especially in the area of low-carb and athletic performance (he’s a cyclist), and is the one of the co-authors of the new Atkins book.</p>
<p>Podcast can be found here:
[The</a> Livin’ La Vida Low-Carb Show With Jimmy Moore](<a href=“http://llvlcshow.libsyn.com/479-dr-steve-phinney-a-low-carb-legend-with-a-brand-new-book]The”>http://llvlcshow.libsyn.com/479-dr-steve-phinney-a-low-carb-legend-with-a-brand-new-book)</p>
<p>Or, in iTunes:
[The</a> Livin’ La Vida Low-Carb Show With Jimmy Moore - Download free podcast episodes by Jimmy Moore on iTunes.](<a href=“http://itunes.apple.com/us/podcast/the-livin-la-vida-low-carb/id324601605]The”>http://itunes.apple.com/us/podcast/the-livin-la-vida-low-carb/id324601605)</p>
<p>The interview was jam packed with interesting stuff, but one section described Dr. Phinney’s first low-carb study as a medical resident back in the 1970s and how it led him to career researching this stuff. At the time, several studies had just been published showing a severe (40%) decline in athletic performance (treadmill endurance testing) two weeks after going on a very low-carb ketogenic diet (like 20 g of carbs per day). He set out to duplicate and confirm these findings, only with one change. He contintued to monitor the performance on ultra low carb for six weeks. He found exactly the same 40% decline in cardio endurance at the two week mark, but – much to his surprise – found that the decline was gone at six weeks of ultra low-carb and performance was back to normal.</p>
<p>What is now understood is that, on an extremely low carb diet (like Atkins induction phase) the body will initially resist the loss of its primary fuel source (carbohydrates) by increasing hunger demands and dialing back metabolism. However, it will then adapt and switch to fat burning as a primary fuel source (remember, the high consumption of carbohydrates elevates blood sugar, stimulates frequent insulin production, and tends to lock fat away in storage ratther than burn it). Once the body has gone through this low-carb adaptation and begun burning stored fat as a fuel athletic endurance returns.</p>
<p>More iinterestingly from a diet perspective, it is this reprogramming to use stored fat as a prefered energy source in the absence of constant carbohydrate supply that explains the fat loss many of us have seen on carb restricted diets and the somewhat surprising lack of hunger (after the intitial adjustment) despite being in a calorie deficit. That has been the shocker for me. I’ve now been averaging under 2000 calories a day for 16 months and it’s not taking any particular “willpower” to keep from eating more. I track my calories, so that factors into decision to grab the candy in the checkout line or not, but it’s not like I’m “starving” for a snack. I don’t feel like I’m dieting.</p>